The present invention relates to a sleeve-type pipe joint for connecting resin or thin metal pipes, particularly to a sleeve-type pipe joint having parts that are not separated in an assembled state and capable of connecting pipes by a single operation with a tool.
Resin pipes made of polyethylene, polypropylene, polybutene, polyvinyl chloride, etc. have widely been used as fluid-conveying pipes such as gas pipes, running water pipes, etc. There are various methods for connecting these resin pipes, and the most widely used method is a type in which a nut is screwed to a joint body, a mechanical connecting method comprising mounting a locking ring member and a packing between the joint body and the nut, and screwing the nut with a wrench to compress the locking ring member and the packing to achieve sealing.
However, the above mechanically connectable pipe joint is disadvantageous in that it is impossible to confirm after the fastening operation whether or not the pipe is fully inserted into the pipe joint, and that it is also difficult to confirm how tight the nut is fastened, resulting in unevenness in the performance of the pipe connection. The confirmation of how well the pipe joint is connected is only a leak test after the fastening operation. Even if the connected pipe joint has passed the leak test conducted for a short period of time after the fastening operation, the detachment of the pipe from the pipe joint and leak are likely to take place during a long period of use.
Accordingly, objects of embodiments of the present invention include providing a sleeve-type pipe joint capable of surely connecting pipes by a simple fastening operation with a relatively small tool, of not causing such problems as insufficient insertion of pipes, insufficient fastening of nuts, erroneous positioning of locking ring members, and unevenness of connecting strength, and of easily confirming after the fastening operation how well the pipes are connected.
The first sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; a ring member having a larger inner diameter than the outer diameter of the pipe; and a resiliently deformable, cylindrical sleeve member disposed between the ring member and the pipe, at least one of an inner surface of the ring member and an outer surface of the sleeve member being provided with a tapered portion, such that when one of the ring member and the sleeve member is slidingly moved, the sleeve member is deformed inward, resulting in tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection; at least one of the ring member and the sleeve member having at least one portion engageable with the joint body, so that when the ring member, sleeve member, and joint body are assembled, the ring member and the sleeve member are locked to the assembled pipe joint.
One example of the first sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; a high-rigidity ring member having a larger inner diameter than the outer diameter of the pipe and at least one portion engageable with the joint body; and a resiliently deformable, cylindrical sleeve member adapted to be pressed into a space between the ring member and the pipe, at least one of an inner surface of the ring member and an outer surface of the sleeve member being provided with a tapered portion, such that when the sleeve member is pressed into a space between the ring member and the pipe, the sleeve member is deformed inward, resulting in tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection; wherein when the ring member, the sleeve member, and the joint body are assembled, the ring member and the sleeve member are locked to the assembled pipe joint.
Another example of the first sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; a resiliently deformable, cylindrical sleeve member having at least one portion engageable with the joint body and a tapered portion on an outer surface; and a high-rigidity ring member adapted to be disposed on an outer surface of the sleeve member and having on an inner surface tapered portion engageable with the tapered portion of the sleeve member, wherein when the ring member is slidingly moved on the sleeve member toward a thicker region of the tapered portion of the sleeve member, the sleeve member is deformed inward, resulting in tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection; and wherein when the ring member, the sleeve member, and the joint body are assembled, the ring member and the sleeve member are locked to the assembled pipe joint.
In the above two examples, the sleeve member preferably has a flange portion, which substantially abuts against a rear surface of the ring member when the connection of the sleeve-type pipe joint is completed. The sleeve member preferably has at least one projection on an outer surface for engaging the ring member when assembled.
A further example of the first sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; a resiliently deformable, cylindrical sleeve member adapted to be abut against a pipe end-abutting surface of the joint body and having a tapered portion on an outer surface; and a high-rigidity ring member adapted to be disposed on an outer surface of the sleeve member and having at least one portion engageable with the joint body and a tapered portion on an inner surface, wherein when the ring member is slidingly moved on the sleeve member toward the joint body, the sleeve member is deformed inward, resulting in tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection; and wherein when the ring member, the sleeve member, and the joint body are assembled, the ring member and the sleeve member are locked to the assembled pipe joint.
In a preferred embodiment, the sleeve member has at least one portion engageable with the ring member, such that both the ring member and the sleeve member resist detachment from the joint body in an assembled sleeve-type pipe joint.
The portion of the joint body with which the ring member or the sleeve member is engageable is preferably an annular groove, an annular projection or a plurality of annular ridges formed in a root portion of the cylindrical projection.
The sleeve member preferably has at least one longitudinal slit in a portion that shrinks in diameter by engagement with the ring member.
In another preferred embodiment, the sleeve member has a flange portion on the rear end side, which substantially abuts against a rear end surface of the ring member when the connection of the sleeve-type pipe joint is completed.
In a further preferred embodiment, the sleeve member has at least one projection on an outer surface, which is engageable with the engaging portion of the ring member to prevent the detachment of the sleeve member when assembled.
In a further preferred embodiment, the sleeve member has a plurality of projections extending forward from its front end, each of which has an outer projection in a tip end portion thereof, and the ring member has a plurality of longitudinal notches separated in a circumferential direction in a front portion thereof, whereby the outer projections of the sleeve member engage the rear end surfaces of the notches of the ring member to prevent the detachment of the sleeve member when assembled.
In a further preferred embodiment, the sleeve member has at least one projection on an outer surface thereof at a position at which the sleeve member does not engage the ring member in an assembled state of the sleeve-type pipe joint, and at which the ring member rides the sleeve member at the time of connection. This prevents the relative sliding movement of the ring member and the sleeve member in a longitudinal direction, by which the sleeve member shrinks in diameter, even when a smaller force than a predetermined level is exerted on the end surface of the sleeve member and/or the ring member before the cylindrical projection of the joint body is inserted into the pipe.
The second sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; and a shrinkable member mounted onto an outer surface of the pipe; the shrinkable member comprising a resiliently deformable sleeve portion having a tapered portion on an outer surface, and a high-rigidity ring portion integrally connected to the sleeve portion via a thin portion; the relative movement of the sleeve portion and the ring portion toward each other causing the ring portion to no longer be integrally connected to the sleeve portion and seating the ring portion on the sleeve portion, whereby the sleeve portion is deformed inward, resulting in the tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection.
One example of the second sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; and a shrinkable member mounted onto an outer surface of the pipe; the shrinkable member comprising a resiliently deformable sleeve portion integrally having at least one portion engageable with the joint body, a flange portion and a shrinkable portion having a tapered outer surface in this order, with at least one slit extending longitudinally, and a high-rigidity ring portion integrally connected to a rear end of the sleeve portion via a thin portion; the sliding movement of the ring portion toward the joint body causing the ring portion to no longer be integrally connected to the sleeve portion and seating the ring portion on the sleeve portion, whereby the sleeve portion is deformed inward, resulting in the tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection.
Another example of the second sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected and a flange portion extending near a root portion of the cylindrical projection; and a shrinkable member mounted onto an outer surface of the pipe; the shrinkable member comprising a resiliently deformable sleeve portion having a tapered outer surface with at least one slit extending longitudinally, and a high-rigidity ring portion integrally connected to a rear end of the sleeve portion via a thin portion; the sliding movement of the ring portion toward the joint body causing the ring portion to no longer be integrally connected to the sleeve portion and seating the ring portion on the sleeve portion, whereby the sleeve portion is deformed inward, resulting in the tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection.
A further example of the second sleeve-type pipe joint of the present invention comprises a joint body having a cylindrical projection adapted to be inserted into a pipe to be connected; and a shrinkable member mounted onto an outer surface of the pipe; the shrinkable member comprising a high-rigidity ring portion, at least one portion engageable with the joint body, which integrally extends from a front end of the ring portion, and a resiliently deformable sleeve portion integrally connected to a rear end of the ring portion via a thin portion; the sleeve portion comprising a shrinkable portion having a tapered outer surface and a flange portion in this order from the side of the joint body with at least one slit extending longitudinally; the sliding movement of the sleeve portion toward the joint body causing the sleeve portion to no longer be integrally connected to a rear end of the ring portion and to enter into a space between the ring portion and the pipe, whereby the sleeve portion is deformed inward, resulting in the tight connection of the inner surface of the pipe to the outer surface of the cylindrical projection.
The above shrinkable member preferably has at least one portion engageable with the joint body. Also, the sleeve portion preferably has a flange portion. Further, the sleeve portion preferably has at least one slit extending longitudinally.